HCA013 is specific for osteocalcin.Osteocalcin (Bone Gla Protein) is a 49 amino acid single chain vitamin K dependent protein (MW 5.8 kDa) made by osteoblasts that is a major component of the non-collagenous bone matrix. Post-translational modification by a vitamin K dependent carboxylase produces three g-carboxyglutamic acid residues at positions 17, 21 and 24, giving osteocalcin a high affinity for calcium. The mature protein contains a single intrachain disulfide bond joining Cys23 to Cys29. The secondary structure is highly calcium dependent and contains 14% a-helix, 20% ß-sheet and 67% random form in the presence of calcium, and 1% a-helix, 20% ß-sheet and 79% random form in the absence of calcium, see Delmas P. D. et al. for details. Sixty to ninety percent of de novo synthesized osteocalcin is incorporated into the bone matrix where it binds to hydroxyapatite during matrix mineralization. The remainder of the osteocalcin is released into the circulation where it can be measured as a sensitive marker of bone formation.
Serum osteocalcin is elevated in diseases characterized by increased bone turnover such as osteoporosis, hyperparathyroidism and Paget’s disease, and low in conditions associated with low bone turnover such as hypoparathyroidism and growth hormone deficiency, see Lee, A. J. et al. for details. Circulating Osteocalcin is unstable as it contains a tryptic cleavage site at amino acids 43-45 near the C-terminus. After cleavage a large fragment containing amino acids 1-43 is formed, which contains both the N-terminus and the middle portion of the protein. Whereas the levels of intact Osteocalcin rapidly decreases, 1-43 Osteocalcin remains stable in serum even after repeated freeze thaw cycles or storage at elevated temperatures, see Lee, A. J. et al. for details. Bio-Rad have matched pairs of monoclonal antibodies recognising amino acids 7-19 and 20-43 (0400-0039 or 0400-0040 and 0400-0041 or 0400-0042), capable of providing a '2 site assay' for the 1-43 fragment.
N.B. Antibody reactivity and working conditions may vary between species.
A bivalent human recombinant Fab selected from the HuCAL® GOLD phage display library. Expressed in E. coli and purified using NiNTA affinity chromatography. This Fab fragment is dimerized via a helix-turn-helix motif. The antibody is tagged with a myc-tag (EQKLISEEDL) and a his-tag (HHHHHH) at the C-terminus of the antibody heavy chain. Supplied lyophilised.
Reconstitute with 0.5 ml distilled water. Care should be taken during reconstitution as the protein may appear as a film at the bottom of the vial. Bio-Rad recommend that the vial is gently mixed after reconstitution.
Metal-chelate affinity chromatography
0.09% Sodium Azide (NaN3) 1% Bovine Serum Albumin
Native bovine bone osteocalcin
Approx. Protein Concentrations
Antibody concentration 0.1 mg/ml after reconstitution
Reagents In The Kit
Preparing The Antibody
Phosphate buffered saline
Prior to reconstitution store at +4oC. After reconstitution store at -20oC. Storage in frost-free freezers is not recommended. This product should be stored undiluted. Avoid repeated freezing and thawing as this may denature the antibody. Should this product contain a precipitate we recommend microcentrifugation before use.
Sold under license of U.S. Patents 6,300,064, 6,696,248, 6,708,484, 6,753,136, European Patent 0,859,841 and corresponding patents.
For in vitro research purposes only, unless otherwise specified in writing by Bio-Rad.
For research purposes only
This product has been reported to work in the following applications. This information is derived from testing within our laboratories, peer-reviewed publications or personal communications from the originators. Please refer to references indicated for further information. For general protocol recommendations, please visit the antibody protocols page.
Where this product has not been tested for use in a particular technique this does not necessarily exclude its use in such procedures. Suggested working dilutions are given as a guide only. It is recommended that the user titrates the product for use in their own system using appropriate negative/positive controls.